Brake and power interlock apparatus



Aug 7, 1945. E5. cooK v BRAKE AND POWER INTERLOCK APPARATUS Filed Sept.30, 1942 5IIAIVEA-JTOIR EuvleSCooW 949g 7 ATTORNEY trated in Fig. 3.

Patented Aug. 7, 1945 UNITED STATES V zssnzos I BRAKE AND rowan mrsnmcxnrraaa'rus Earle 8. Cook, Wilkinsb'urg, Pa., assigno'r The .WestlnghouseAir Brake Company, Wilmerding, Pa., a corporation of PennsylvaniaApplication September 30,1942, Serial No. 460,288

21 Claims.

I This invention relates to brake and power interloclr apparatus andmore particularly to means for causing the brakes on avehicle to beapplied automatically in case of failure of the propelling power for thevehicle.

the controller which controls the supply of elec- 'tric current to themotor for propelling the locomotive has diiferent positions for causingoperation of the motor in either on direction or the reverse to move thelocomotiv either forwardly or backwardly, and at times with thelocomotive running-in one direction the controller is moved to theposition for causing reverse operation of the motor or for so-calledbucking the motor in order to brake the locomotive. If at the time thecontroller were operated to thus brake the locomotive-there would be noelectric power, due

for instance to the trolley wheel having jumped of such an arrangementwhich also embodies means for effecting a release of the automaticapplication of brakes with the electric power to the locomotive cut offin case for instance it is 1 desired to move the locomotive for repairsbefor the electric power is restored. I

' Otherobjects and advantages will be apparent from the following moredetailed description of, the invention.

Inithe accompanying drawing; Fig. 1 is 8, diarammatic view, with thepartsshown mainly in elevation, of a brake and power control system fora locomotive; Fig. 2' is a diagrammatic view of a portion of theapparatus shown in..F'ig.,1 and embodying a modification of theinvention; 3 is a diagrammatic view of a portion of the apparatus shownin Fig. 1 and embodying another modification thereof; and Fig. 4 is aview similar to Fig. 2 but embodying the modiiicationillus- Description1 10. 1

The brake system employed for illustrating the invention may beidenticalto the hydraulic brake system disclosed in'the pendingapplication of Rankin J. Bush, Serial No. 440.823 filedApril '28,

-' Inview of this the brake valve will be described I.

(on. soc-1) 1942, and therefore comprises an accumulator l arranged tobe charged by way of a pipe 2 with 1 liquid under pressure delivered bya hydraulic pump not shown but contained inl'a liquid reser- 5 voir orsump 3.. -An electric motor 4 is provided On certain electricallyoperated locomotives,

for operating the hydraulic pump and current for operating said motormaybe obtained from any suitable'source such as a trolley wire 5, atrolley 8 and wires I and 8, the connections between the 10 wires 1 and8 being controlled by an electric switch 9 associated with theaccumulator I. This switch is operative by the accumulator when theamount of liquid under pressure therein is reduced to a certain minimumdegree, to close the circuit- 15 through wires 1 and a and thereby tothe motor 4 to cause operation thereof and of the pump operated therebyto displaceliquid under pressure into the accumulator I. When the amountof liquid in the accumulator is thus increased to a maximum desireddegree, the switch 9 operates automatically to open the circuit throughmotor to stop same and thereby the pump. In this manner the motor 4 andpump will be caused to automatically operate and then-be stopped,. asrequired, to maintain a desired reserve of. liquid under pressure intheaccumulator at all '1 times, as described in detail in the abovereferred to Bush application in view of which a more detaileddescription is not deemed essential herein to a clear understanding ofthe invention.

Liquid under pressure from the accumulator is constantly suppliedthrough a supply pipe III to a brake valve device II which may beidentical to that fully disclosed and described in Patent 2,324,910issuedon July 20, 1943, to Earle 3. Cook.

herein only briefly. I

The brake valve device I l'comprises an operating handle l2 which isoperable by'the operator device I, which will be, later described, and apipe ll to a brake cylinder device ii for eflecting operation of saidbrake cylinder device -'to apply the brakes'on the locomotive. Thehandle i2 is also operable by the operator to a brake release positionto close communication betweenpipes l0 and I; for cutting oil thesupply'of liquid under V pressure to the brake cylinder device l6 and toopen pipe it to a sump pipe ll leading to the liquid reservoir or sump 3to thereby relieve the pressure of liquid in the brake cylinder deviceii 5 for releasing the brakes on the locomotive.

The power system for the locomotive may, by way of illustration,comprise a propulsion motor l8 and a manually operable power controllerl9 arranged to control the supply of electric power from the trolley 5to said motor for causing same to operate to propel the locomotive. Thecontroller l9 may comprise a control lever 20 having a position such asshown for causing the motor l8 to operate to drive the locomotive in onedirection, and another positionsuch as indicated byv a dot and dash line2| for causing the motor 18 to operate to drive the locomotive in theopposite direction. With the lever 20 in either of its positions and thelocomotive running in a corresponding direction, the locomotive may bebraked if said lever is moved to its other position due to the resultingaction of the motor l8 to oppose continued movement of the locomotive,as is well known. If at the time the controller I9 is operated to causethe motor 18 to brake the locomotive there should be no electric currentavailable from trolley wire 5- for supply to the motor l3, due, forexample, to trolley 5 having jumped off-oi! the trolley wire 5, thenobviously the motor l8 will fail to operate to brake the locomotive anddamaging or wrecking of the locomotive and possibly of a train mayresult. This is liable to occur even though the locomotive is providedwith a fluid pressure, brake system such as above described,particularly where it has become a custom or habit to employ the motorH! for braking purposes.

According to the invention I provide means to operate automatically incase of failure of the 38 is provided for turning the plug valve 35 fromits normal position shown to a brake release position in which saidhandle will occupy a position such as indicated by a dash and dot line39. In

' the normal position of the plug valve the water way 3! establishescommunication between pipe 34 and a pipe 40 leading to the double checkvalve device l4, while in'the brake release position said communicationis closed and the water way 31 opens pipe 40 to a pipe 4| leading topipe 3| which is open through pipe II to the sump 3.

The double check valve device l4 comprises a casing having two endoutlets one connected to pipe l3 and the otherto pipe 40 and also havinga side outlet Open to pipe IS. A double check valve 42 slidably mountedin the casing is arranged to control communication between the outletsopen to pipes i3 and lit-and the outlet open to pipe I5.

In operation, the plug valve 35 of cook 35 is normally positioned asshown in the drawing so as to open pipe 40 to pipe 34, and with thesolenoid 32 of the magnet valve energized by ourrent supplied from thetrolley wire 5 to the controller i 9 for propelling the locomotive, themagnet valve.2| is. open so that pipe 34 is open to the sump 3. Thus thelower face of the double check valve 42 is open to the sump 3 so thatsaid valve may shift to the position shown in the drawing under pressureof fluid supplied to pipe l3 by operation of the brake valve device IIto thereby supply of electric current to the locomotiv to apply thebrakes on the locomotive by operationof the brake cylinder device l6 soas to prevent damaging or wrecking of the locomotive under suchacondition. As shown in Fig. 1 this means comprises a magneticallyoperated valve device 25 and the double check valve device l4.

The magnet valve device 25 comprises a pair of oppositely seating poppetvalves 23 and 21 which are contained in a chamber". The valve 26 isarranged to control communication between chamber 28 and a chamber 29 towhich is connected a branch of the liquid pressure supply pipe l0 sothat'said chamberis constantly supplied with fluid under pressure. Thevalve 21 isprovided to control communication between chamber 28 and achamber 30 which is open to a pipe 3| leading to the sump pipe I!whereby chamber 30 is constantly open to the sump.

The magnet valve device 25, further comprises a solenoid 32 which isconnected to wire I and therefore arranged to be energized when electriccurrent is supplied from the trolley wire 5 to the motor controller i9.A failure of the 'supply of electric current to the controller l3through wire 1 will result in deenergization of solenoid 32.

Energization of solenoid 32 is adapted to unseat valve 21 and seat valve26, while a spring33 indisconnect the brake cylinder pipe l5 from pipeandopen the brake cylinder pipe to pipe 13, whereby the operation of thebrake cylinder I '8 to control the brakes on the locomotive may becontrolled by the brake valve device I I.

If the supply of electric current from trolley wire 5 to the motorcontroller IBshould for any reason fail, the solenoid 32 of the magnetvalve device 25 will become deenergized and permit spring 33 to openvalve 25 vandclose valve 21 to thereby permit liquid under pressure tonow fro the acculator I to pipe 34 and thence through cock 35 and pipe40 to the lower face of the double check valve 42. With the brake valvedevice H in its brake release position and the opposite face of thedouble check valve thus open to the sump I P p chamber 29 is provided toopen valve 26 and close valve 21 upon .deenergization of solenoid 32.'It.

will thus be seen that when the locomotive is in use and electriccurrent is being supplied to the motor controller l9 the solenoid 32will be enersized to unseat valve .21 and open chamber 23 to the sumppipe 3|, while in case the supply of electric. current Show fail thesolenoid will be deenergized to-allow spring. 33 to open valve 26 andhence permit liquid under pressure to flow into chamber 28.

Chamber 2.8 is connected by a pipe 34 to a cock 35 which comprises acasing containing a plug valve 35 provided with a water way 31. A handlell, the accumulator pressure supplied through pipe 34 and acting on thedouble check valve will shift same to its upper position to closecommunication between pipes l5 and I3 and to open pipe l5 to pipe 40.Liquid supplied from the accumulator to pipe 40 will then flow to pipel5 and thence to the brake'cylinder device to actuate same to apply thelocomotive brakes.

It will nowbe seen that when it has become customary to employ thelocomotive motor i8 for braking purposes a failure of the supply ofelectric current to the controller I! to provide such braking can notresult in a failure to obtain braking and hence wrecking or damaging orthe locomotive, since such failure or current will automatically resultin deenergization of solenoid 32 to cause an application of. brakesbyliquid .If, however, it is desired or necessary to move the locomotivebefore the cause for failure of electric current to the controller I9and thus solenoid 32 has been determined and proper repair effected, thehandle 38 of cock 35 may be operated to turn the plug valve 36 to itsbrake release position in which the pressure of liquid in the brakecylinder device It will be dissipated throughpipesfill, 4|, 3| and IT tothe sump 3. The-brakes on the locomotive will b thus released to permitmovement of the locomotive.-

, When or before the locomotive is again placed in service the handle 38and thereby the plug valve 36 of cock 35 must be returned to theirnormalpositions shown to again connect the double checkvalve' device I4to pipe 34, so that in case of subsequent failure of the supply ofcurrent to the controller the brakes on the locomotive will again beautomatically applied in response to such failure in the same manner asabove described.

- Description Fig. 2

If desired, an electro -magnet device 45 connected into the hydraulicbrake equipment as shown in Fig.2 may be employed insteadof theelectro-magnetic device and. double check valve I4 to accomplish thesame result.

' The electromagnet device 45 comprises a solenoid 46 connected towire Ito function identically to the solenoid 32 of the magnet device 25 5shown in Fig. 1. The magnet device 45further comprises two alignedpoppet valves 4? and 48 containedin chambers) and 50 respectively andhaving fluted stems which engage each other in an intermediate chamber5I. The chamber 49 is connected to the liquid supply pipe I!) from theaccumulator I. The chamber 50 is connected to pipe I3 leading tothe'brake valve device I I, while chamber 5| is connected to pipe I3leading to I the'cock'35. The brake cylinder pipe I5 is connected tovthe cock at the location where pipe was connected in the structure shownin Fig; 1.

In operation, with the cook 35 in its normal condition shown in Figs. 1and-2, and withgthe solenoid 46 energized the valve 41 will be seatedand the valve48 open to connect the brake valve device II with the brakecylinder device I5 by way of pipe I3, past valve 48 tochamber 5| andthence through pipe 34, cook 35 and pipe I5. Under this normal conditionof parts, the opera,- tion. of the brake cylinder device I6 to controlthe brakes on the locomotive may be controlled by the brake valvedeviceI I in the same manner as before described, as will be readily seen.

If, however, the supply of'current to the controller I9 should fail forany reason, the resultant deenergization of solenoid 46 permit a spring52 in valve chamber to seat valve 48 and unseatvalve '41 and'thusconnect the brake cylinderdevice I6 directlyto the accumulator pressurepipe I0, whereupon the locomotive brakes I will be automaticallyapplied. If it is desired to effect a release of the brake applicationbefore restoration of the supply of electric current to the controllerI9 this may be done by operation of cook 35 in the same manner asdescribed in connection with the structure shown in Fig. g

' Description Figs. {and '4 accumulator I while dissipating that fromthe magnet device 25 or 45.

' readily be seen.

Nevertheless, in order to ensure that such an undesirable condition cannot obtain, the cook 35 in the structures shown in Figs. 1 and 2 may bedispensed with and acock. 55 added to said structures as shown in Figs.3 and 4, respectively.

The cook 55 comprises a plug valve 51 having a waterway 58 and ahandle59 for turning the plug valve from a normal closedposition as shown inFig. 3 to a brake release position in which the handle will occupy aposition such as indicated by a dot and dash line 60. A I

In both of the structures shown in Figs. 3 and 4 the cook 55' isarranged to control a communication between the sump pipe SI andthe'liquid pressure supply pipe I0 leading to the magnet valve device 25or 15. The cock 55 when in its normal position shown closes thiscommunication so that'the brakes on the locomotive may be controlledfrom the brake valve device- It and also be applied in case theelectro-magnet device 25 or 45 becomes deenergized due to failure ofelectric power, in the same manner as before described in connectionwith the structure, hown in Figs. 1 and 2. I

An application of brakes effected upon deenergization of theelectro-magnet device 25 or 45 maybe released in these structures byturning cock 55 to its brak release position for connecting pipe Ill tothe sump pipe II since the brake cylinder device IE will at this time beopen to the pipe Iii. Since the accumulator I- is always open to pipeIll it will also be noted that liquid pressure in the accumulator willbe dissipated to the sump upon dissipating that from the brake cylinderdevice to release the locomotive brakes. The brakes on the locomotivecan not again be applied by the brake valve device H until after thepressure in the accumulator has been restored, and such restorationrequires that the cock 55 be returned to its normal position for closingcommunication between the accumulator and sump and as an indirect resultinsures an automatic application of brakes in case of failure ofthesupply of electric current to the electro- Summary.

It-will now be seen that I have provided means to cause automatically anapplication of brakes on a locomotive in case of failure of the propellng power to the locomotive, sons to insure that the locomotive will hebrought to a stopunder such a conduitio-n of emergency. Means are alsoprovided which permits the release of brakes on the locomotive in caseit is desired to move the locomotive for repairs or for any other reasonprior to restoration of power, and this release means may be either in aform to prevent what might be considered an undesirable loss'of liquidunder pressure-from the accumulator, or in another form which insures{that the automatic brake applying means will function as intended whenthe locomotive is again placed in service with other parts of the brakesystem inan opera tive condition.

Having now described my invention, what I claim as new and desire tosecure by Letters Patent, is: r

1. In a brake and power control apparatus for a vehicle, in combination,a source of fluid under pressure, brake cylinder means operable by fluidunder pressure to apply the brakes on said vehicle and upon release offluid under pressure to release the brakes on said Vehicle, manuallycontrolled means having a brake release position for releasing fluidunder pressure from said brake cylinder means and being movable out ofsaid release position to open communication between said source of fluidunder pressure and brake cylinder means for supplying fluid underpressure to said brake cylinder means, a source of power for propellingsaid vehicle, and mechanism, including means controlled by said power,and operable upon failure of said power to effect closure of saidcommunication and to establish another communication between said sourceof fluid under pressure and said brake cylinder means for supplyingfluid under pressure to said brake cylinder means.

2. In a brake and power control apparatus for a Vehicle, in combination,a source of fluid under pressure, brake cylinder means operable by fluidunder pressure to apply the brakes on said vehicle and upon release offluid under pressure to release the brakes on said vehicle, manuallycontrolled means having a brake release position for releasing fluidunder pressure from said brake cylinder means and being movable out ofsaid release position to open communication between said source of fluidunder pressure and brake cylinder means for supplying fluid underpressure to said brake cylinder means, a source of power for propellingsaid vehicle, and mechanism including means controlled by said power andoperable upon failure of said power to effect closure of saidcommunication and to establish another communication between said sourceof fluid under pressure and said brake cylinder means for supplyingfluid under pressure to said brake cylinder means, said mechanism beingoperable by said power to close the last named communication and toprovide for opening of the first named communication.

3. In a brake and power control apparatus for a vehicle, in combination,a source of fluid under pressure, brake cylinder means operable by fluidunder pressure to apply the brakes on said vehicle and upon release offluid under pressure to release the brakes on said vehicle, manuallycontrolled means having a brake release position for releasing fluidunder pressure from said brake cylinder means and being movable out ofsaid release position to open communication between said source of fluidunder pressure and brake cylinder means for supplying fluid underpressure to said brake cylinder means, a source of power for propellingsaid vehicle, and mechanism including means controlled by said power andoperable upon failure of said power to effect closure of saidcommunication and to establish another communication between said sourceof fluid under pressure and said brake cylinder means for supplyingfluid under pressure to said brake cylinder means, said mechanism beingoperable by said power to close the last named communication and to openthe first named communication.

4. In a brake and; power control apparatus for a vehicle, incombination, brake cylinder means operable by fluid under pressuretoapply the brakes on said vehicle and upon release of fluid underpressure to release said brakes, manually controlled means operable tosupply fluid under pressure to a pipe for supply to said brake cylindermeans and having a brake release position for releasing fluid underpressure from said pipe, a source of power for propelling said vehicle,means controlled by said power and conditionable thereby to releasefluid under pressure from a second pipe and operable upon failure ofsaid power to supply fluid under pressure to said second pipe for supplyto said brake cylinder means. and a double check valve controllingcommunication between the two pipes and said brake cylinder means andoperable by fluid under pressure supplied to either of said pipes toopen communication between the pipe supplied with fluid under pressureand said brake cylinder means and to close communication between saidbrake cylinder means and the other pipe.

5. In a brake and power control apparatus for a'vehiole, in combination,brake cylinder means operable by fluid under pressure to apply thebrakes on said vehicle and uponrelease of fluid under pressure torelease said brakes, marually controlled means operable to supply fluidunder pressure to a pipe for supply to said brake cylinder means andhaving a brake release position for releasing fluid under pressure fromsaid pipe, a source of power for propelling said vehicle, and meanscontrolled by said power controlling communication between said pipe andbrake cylinder means and conditionable by said power to open saidcommunication and operable upon failure of said power to close saidcommunication and to open another communication for supplying fluidunder pressure to said brake cylinder means.

6. In a brake and power control apparatus for a vehicle, in combination,a source of power for propelling said vehicle, brake cylinder meansoperable by fluid under pressure to apply the brakes on said vehicle andupon the release of fluid under pressure to release the brakes on saidvehicle, manually controlled means operable to supply fluid underpressure to and release fluid under pressure from said brake cylindermeans, and safety means controlled by said power and operable uponfailure thereof to supply fluid under pressure to said brake cylindermeans and to render said brake cylinder means non-controllable by saidmanually controlled means and operable by said power to provide forcontrol of said brake cylinder means by said manually controlled means.

7. In a brake and power control apparatus for a vehicle, in combination,a source of power for propelling said vehicle, brake cylinder meansoperable by fluid under pressure to apply the brakes on said vehicle andupon the release of fluid under pressure to release the brakes on saidvehicle, manually controlled means operable to supply fluid underpressure to and release fluid under pressure from said brake cylindermeans, safety means controlled by said power and operable upon failurethereof to supply fluid under pressure to said brake cylinder means andto render said brake cylinder means non-controllable by said manuallycontrolled means and operable by said power to provide for control ofsaid brake cylinder means by said manually controlled means, andmanually controlled means arranged to release fluid under pressure fromsaid brake cylinder means'with said safety means in the condition fluidunder pressure toand'release fluid under pressure; from said; brakecylinder: means, safety means-controlled by said power an-d'operableupon :failure thereof to supply fluid under pressure to said brakecylinder means andi to render said brake cylindermeans non-controllableby said manually controlled meansand operable by said power-to providefor control of saidbrakecylinder means by said manually contrclled'means, and

I manually controlled means arranged to close-communicationbetweensaid-:safetymeans and brake cylinder means and to release fluidunder pressure from said brake cylinder means. 2 1 w .9. A'brake :systemfor an electrically propelled vehicle comprising in-ccmbination-vvith asource of electric power for propelling thevehiclabrake cylinder meanoperable byifluid under pressure to apply the brakes on saidvehicle andupon release :of flui-d under pressure to release the brakes onsaidzzvehicle', and a brake valve device operable to supply, fluid underpressure to said "brake cylinder means and movable to a position 'forreleasing fluid under. pressure from said brake cylinder means, of andelectro-magnet energizable upon supply of electric power to saidvehicle and deenergizable upon failure. of .said power, and valvemechanism conditionable in accordance with the condition of saidelectro-magnet and operable upon ideenergization thereof to supply fluidunder T pressuretosaid brake cylinder means and close communicationbetween said, brake cylinderl means and brake valve device and operableupon energization of said electro-magnet to cut ofi supply. of fluidfrom said valvemechanism to said or pressure in said brake cylindermeans by said brake valvedevice. 1 r. H 10, Ajbrake system for anelectrically propelled vehicle comprising in combinationwith a,,so urceof electric power for propelling the vehiclfiibrake cylinder ,meansoperable by fluid under pressure to apply the brakes on said vehicle andupon release offluid-under pressureto release the brakes on-saidvehicle, and a brake valve device operable to supply fluid underpressure to said brake cylinder means and movable to a position forreleasing fluid under pressure from said brake cylinder means, of anelectr c-magnet energizable upon supplyfof electric power to saidvehicle and deenergizable upon 'failure of said power, valve mechanismconditionablein accordance with the condition of said electromagnetandoperable upon deenergization thereof t supply fluid under pressure tosaid brake cylinder means andclose communication between said, brakecylinder means and brake valve device and operable upon energization ofsaid electro-magnet to out off supply of fluid vfrom said valvemechanism to said I brake cylinder means andto provide for control ofpressure in said brake cylinder means by said brake -valve, device andvalve means operable manually to release fluid under pressure from saidbrakecylinder vmeans with said valve mechanism operable in response todeenergization ofsaid elcctro masnct. J l

,ll, A wd faulic brake system for an electrically der means and manuallycontrolled ;,device, said propelled vehicle comprising in combinationwith a source of electric power for propelling said vehicle, a source of:.liquid under pressure, a liquid sump from which liquid is drawn andpumpedrinto said source of pressure, brakecylinder means arranged to beoperated upon connection with said source of liquid pressure to applythe brakes on the vehicle and upon connections with said sump to releasethe-brakeson theveh-icle, and a manually controlled device operable toopen said .brakecylinder means either to' said source ofliquid pressureor to said sump, of an electro-magnet ener- =gizable upon supply ofelectric powerfromisaid sourceto said vehicle for propelling same anddeenerg-iza'ble upon-failure of said supply of electricpower, and valvemechanism conditionable in accordance with the condition of saidelectroemagnet and operable upon deenergization thereof to supply liquidunder pres-sure from said source to said brake cylinder means and to.efiect closure of the communication between said brake cylinq valvemechanism being-operable in responseto energization of said electro-magnet toicut ofi the supply of liquid under pressure to -said brakecyL- hicle, a source of liquidflunder pressure. a liquid brake cylindermeans and to provide for control sum-p from whichliquidis drawn andpumped into said source of pressure, brake cylinder means anran-gedto-be operatedupon connection withsaid source of liquid pressure toapply the brakes on the vehicle and upon connection with said sumptorelease the brakes on the vehicle, and a manually controlled deviceoperable to, open said-brake cylindermeanseither to saidsource of liuidpressure orltosai d Sumner an electroema'gnet energizable upon.supplyof electric power from said source to said vehicle forpropelling'same and deenergizable upon failure of said supply ofelectricpower, valve i mechanism"conditionable' in accordance with the conditionof said electromagnet and operable upon .deenergization thereof tosupply liquid under pressure from said source to said brake cylindermeans and to 'efiect closure of the: communication betweensa'idbrakecylinder means and manually controlled device, said valve mechanismbeing operable in response to'eneirgiz'ation of said, electro-magnet tocut on the supply of liquid under pressure tofsaid brake cylinder meansby said valve mechanism and to provide for control of said brakecylinder means bysaid manually controlled device, and'a manuallyoperable valve controlling a communi'cation between said brake cylindermeans and sump and nore mally closing same and operable to open suchcommunication for releasing liquid under'pressure from said brakecylinder means to said sump.

1'3. Ahydraulic brake system for an electrically propelled vehiclecomprising'in combination with a source of electric power for propellingsaid vehicle, a source of liquid under pressure, a liquid sump fromwhich liquid is drawn and p mped into said source of pressure, brakecylindermeans arranged to be operated upon connection with said sourceof liquid pressure to apply the brakes on the vehicle and uponconnection with said sump to release the brakes on the vehicle, and amanually controlled device operable to open said brake, cylinder meanseither to said source of liquid pressureor to said sump, of anelectrolmagnet energizable upon supply of electric power from saidsource to said vehicle for propelling same, and deenergizable uponfailure of said supply of electric power, valve mechanism conditionablein accordance with the condition of said electro-magnet and operableupon deenergization thereof to supply liquid under pressure from saidsource to said brake cylinder means and to efiect closure of thecommunication between said brake cylinder means'and manually controlleddevice, said valve mechanism being operable in response to energizationof said electro-magnet to cut off the supply of liquid under pressure tosaid brake cylinder means by said valve mechanism and to provide forcontrol of i said brake cylinder means by said manually controlleddevice, and a manually operable valve controlling the fluid supplycommunication between said mechanism and brake cylinder means andnormally opening such communication and operable to close same and opensaid brake cylinder means to said sump.

i 14. A hydraulic brake system for an electrically propelled vehiclecomprising in combination with a source of electric power for propellingsaid vehicle, a source of liquid under pressure, a liquid sump fromwhich liquid is drawnand pumped into said source of pressure, brakecylinder means arranged to be'operated upon-connection with said sourceof liquid pressure to apply the brakes on the vehicle and uponconnection with said sump to release the brakes on the vehicle and' amanually controlled device operable to open said brake cylinder meanseither to said source of liquid pressure or to said sump, of anelectromagnet energizable upon supply of electric power from said sourceto said vehicle for propelling same and deenergizable upon failure ofsaid supply of electric power, valve mechanism conditionable inaccordance with the condition of said electro-magnet and operable upondeenergization thereof to supply liquid under pressure from said sourceto said brake cylinder means and to effect closure of the communicationbetween said brake cylinder means and manually controlled device, saidvalve mechanism being operable in response to energization of saidelectro-magnet to cut off the supply of liquid under pressure to saidbrake cylinder means by said valve mechanism and to provide for controlof said brake cylinder means by said manually controlled device, and aman ually operable valve controlling communication between said sourceof liquid under pressure and said sump and normally closing suchcommunication and operable to open same for releasing liquid underpressure from said source of liquid pressure and thereby from said brakecylinder means when open to such source by said mechanism conditioned inresponse to deenergization of said electro-magnet.

15. A hydraulic brake system for an electrically propelled vehiclecomprising in combination with a source of electric power forpropelling'said vehicle, a source of liquid under pressure, a liquidsump from-which liquid is drawn and'p'umped into said source ofpressure, brake 'cylindermeans arranged to be operated upon connectionwith said source of liquid pressure to apply the brakes on the vehicleand upon connection with "said sump to release the brakes on thevehicle, and a manually controlled brake valve deviceoperable to open apipe to either said source of liquid pressure or to said sump forthereby either supplying fluid under pressure to said pipe or releasingfluid under pressure therefrom for controlling said brake cylindermeans, magnetically controlled means energizable upon supply of electriccurrent from said power source to said vehicle for propelling same toopen a second pipe to said sump and deenergizable upon failure of saidelectric current to open said second pipe to said source of liquidpressure for supplying liquid under pressure to said second pipe, and adouble check valve connecting the two pipes to said brake cylinder meansand operable by liquid under pressure supplied to either pipe to opensame to said brake cylinder means and to close communication betweensaid brake cylinder means and the other pipe.

16. A hydraulic brake system for an electrically propelled vehiclecomprising in combination with a source of electric power for propellingsaid vehicle, a source of liquid under pressure, a liquid sump fromwhich liquid is drawnand pumped into said source of pressure, brakecylinder means arranged to be operated upon connection with said sourceof liquid pressure to apply the brakes on the vehicle and uponconnection with said sump to release the brakes on the vehicle and amanually controlled brake valve device operable to open a pipe to eithersaid source of liquid pressure or to said sump for thereby eithersupplying fluid under pressure to said pipe or releasing fluid underpressure therefrom for controlling said brake cylinder means,magnetically controlled means energizable upon supply of electriccurrent from said power source to said vehicle for propelling same toopen a second pipe to said sump and deenergizable upon failure of saidelectric current to open said second pipe tosaid source of liquidpressure for supplying liquid under pressure to said second pipe, adouble check valve connecting the two pipes to said brake cylinder meansand operable by liquid under pressure supplied to either pipe to opensame to said brake cylinder means and to close communication betweensaid brake cylinder means and the other pipe, and a valve controllingcommunication between said sump and source of liquid pressure andnormally closing same and operable manually to open same and therebyopensaid brake cylinder means to said sump with i said magneticallycontrolled means deenergized.

' 17. A hydraulic brake system for an electrically propelled vehiclecomprising in combination with a source of electric power for propellingsaid vehicle, a source of liquid under pressure, a liquid sump fromwhich liquid is drawn and pumped into said source of pressure, brakecylinder means arranged to be operated upon connection with said sourceof liquid pressure to apply the brakes on the vehicle and uponconnection with said sump to release the brakes on the vehicle and amanually controlled brake valve device operable to open a pipe to eithersaid source of liquid pressure or to said sum for thereby eithersupplying fluid under'pressure to said pipe or releasing fluid underpressure therefrom for controlling said brake cylinder means,magnetically controlled means energizable upon supply of electriccurrent from said power source to said vehicle for propelling same toopen a second pipe to said sump and deenergizable upon failure of saidelectric current to open said second pipe to said source of liquidpressure for supplying liquid under pressure to said second pipe, 2.double check valve connecting the two pipes to said brake cylinder meansand operable by liquid under pressure supplied to either pipe to opensaid magnetically controlled means and. said double check valve andnormally openingsuch communication and operable to close same and openthe connection with said double check valve to said sump for releasingliquid under pressure from said brake cylinder means.

18. A hydraulic brake system for an electricall propelled vehiclecomprising in combination with a source of electric power 'forpropelling I said vehicle, a source of liquid under pressure, a liquidsump from which liquid is drawn and pumped into said source of pressure,brakecylinder means arranged to be operated upon connection with saidsource of liquid pressure to apply the brakes on the vehicle and uponconnection with said sump to release the brakes on supply of electricpower from said source for propelling the vehicle and deenergizable uponfailure of said electric power, and valve means controlled by saidelectro-magnet controlling communication between said brake valve deviceand brake cylinder means and operable to open said communication uponenergization of said electro-magnet and to close said communication upondeenergization of said electro-magnet, said valve means also controllinga communication between said source of liquid pressure and said brakecylinder means and being operable to close same upon energization andtoopen same upon deenergization.

19. A hydraulic brake system for an electrically propelled vehiclecomprising in combination with a source of electric power for propellingsaid vehicle, a source of liquid under pressure, a liquid sump fromwhich liquid is drawn and pumped into said source of pressure, brakecylinder means arranged to be operated upon connection with said-sourceof liquid pressure to apply the brakes on the vehicle and uponconnection with said sump to release the brakes on the vehicle, amanually controlled brake valve device operable to open said brakecylinder means either to said source of liquid pressure or to said sump,of an electro-magnet energizable upon supply of electric power from saidsource for propelling the vehicle and deenergizable upon failure of saidelectric power, valve means controlled by said electro-magnetcontrolling com-' tro-magnet and to close said communication upl ondeenergization of said electro-magnet, said valve means also controllinga communication between said source of liquid pressure and said brakecylinder means and being operable to close same upon energization and toopen same upon deenergization, anda manual valve arranged to opencommunication between said brake cylinder means and sump for releasingthe .brakes.

v 20., A brake and power interlock arrangement for an electricallypropelled vehicle having a hydraulic brake system comprising a source ofliquid pressure, a liquid sump, brake cylinder means operable by liquidpressure from said source to brake the vehicle and upon connection withsaid sump to release said brake and an operators brake valve devicearranged to open said brake cylinder means either to said source or tosaid sump, said interlock arrangement comprising an electro-magnetenergizable by electric power. supplied to propel the vehicle anddeenergizable upon failure of said electric power and valve meansconditionable in accordance with the condition of said magnet andoperable upon deenergization thereof to efiect closure of thecommunication between said brake cylinder means and brake valve deviceand to open said brake cylinder means to said source of liquid pressureand operable upon energization to close the communication between saidbrake cylinder means and source and to provide for control of said brakecylinder means by said brake valve device.

21. A brake and power interlock arrangement for an electricallypropelled vehicle having a hydraulic brake system comprising a source ofliquid pressure, a liquid sump, brake cylinder means operable by liquidpressure from said source to brake the vehicle and upon connection withsaid sump to release said brake, and an operators brake valve devicearranged to open said brake cylinder means either to said source or tosaid sump,'said interlock arrangement comprising an electro-magnetenergizable by electric power supplied to propel the vehicle anddeenergizable upon iailure of said electric power, valve meansconditionable in accordance with the condition of said magnet andoperable upon deenergization thereof to effect closure of thecommunication between said brake cylinder means and brake valve deviceand to open said brake cylinder means to said source of liquid pressureand operable upon energization to close the communication between saidbrake cylinder means and source and to provide for control of said brakecylinder means by said brake valve device, and a manually adjustablecock controlling a communication between said brake cylinder means andsump and normally closing same and operable to open said communicationfor releasing liquid under pressure from said brake cylinder means tosaid sump with said valve means in the position for supplying liquidunder pressure to said brake cylinder means.

EARLE S. COOK.

